BVITAC Vitamin C contributes to normal energy-yielding metabolism and reduction of fatigue. BVITAC contributes to the normal function of the immune system. BVITAC increases iron absorption. BVITAC contributes to the normal formation of collagen, which is essential for the normal function of cartilage, blood vessels, bones, gums, skin, and teeth. Zinc contributes to normal DNA synthesis. Zinc contributes to the normal function of the immune system. Zinc contributes to the maintenance of normal bones, hair, nails, and skin.